[S390] replace diag10() with diag10_range() function

Currently the diag10() function can only release one page. For exploiters
that have to call diag10 on a contiguous memory region this is suboptimal.
This patch replaces the diag10() function with diag10_range() that is
able to release multiple pages. In addition to that the new function now
allows to release memory with addresses higher than 2047 MiB. This was
due to a restriction of the diagnose implementation under z/VM prior to
release 5.2.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/diag.h b/arch/s390/include/asm/diag.h
index 72b2e2f..7e91c58 100644
--- a/arch/s390/include/asm/diag.h
+++ b/arch/s390/include/asm/diag.h
@@ -9,9 +9,22 @@
 #define _ASM_S390_DIAG_H
 
 /*
- * Diagnose 10: Release pages
+ * Diagnose 10: Release page range
  */
-extern void diag10(unsigned long addr);
+static inline void diag10_range(unsigned long start_pfn, unsigned long num_pfn)
+{
+	unsigned long start_addr, end_addr;
+
+	start_addr = start_pfn << PAGE_SHIFT;
+	end_addr = (start_pfn + num_pfn - 1) << PAGE_SHIFT;
+
+	asm volatile(
+		"0:	diag	%0,%1,0x10\n"
+		"1:\n"
+		EX_TABLE(0b, 1b)
+		EX_TABLE(1b, 1b)
+		: : "a" (start_addr), "a" (end_addr));
+}
 
 /*
  * Diagnose 14: Input spool file manipulation